Fracturing pump arrangement using a plunger with an internal fluid passage

In certain embodiments, the present disclosure is directed towards an apparatus comprising a plunger assembly. The plunger assembly is configured to reciprocate in a plunger bore formed within a fluid end body. The plunger assembly comprises a plunger body, a valve seat, and a valve assembly. The plunger body has a first end, a second end, and a first bore interconnecting the first and second ends. The valve seat is situated within the plunger body adjacent the first end. The valve assembly is positioned adjacent the first end of the plunger body. The valve assembly comprises a valve body configured to engage the valve seat, a retainer installed within the first bore, a stem, and a spring. The stem has a first end connected to the valve body and an opposed second end. The retainer rotates with the stem and is free to move axially along the stem. The spring is concentric with the stem and is installed within the first bore. The spring is situated between the retainer and the second end of the stem.

In another aspect, certain embodiments of the present disclosure are directed towards an apparatus comprising a fluid end body, a plunger, a valve assembly, a conduit, and an inlet manifold. The fluid end body comprises a plunger bore. The plunger is configured to reciprocate within the plunger bore. The plunger comprises a first end, an opposed second end, a first opening formed in the first end, a second opening formed in the second end, a fluid bore extending inside the plunger and joining the first and second openings, and a valve seat installed in the plunger adjacent the second opening. The valve assembly comprises a valve body configured to seal against the valve seat. The conduit has opposed first and second ends. The first end is attached to the first end of the plunger via an inlet component. The inlet manifold and second end of the inlet conduit are situated above the first end of the fluid end conduit and the plunger.

U.S. Pat. No. 11,578,710 (hereinafter referred to as “the '710 patent”), entitled ‘Fracturing Pump with In-Line Fluid End’, issued on Feb. 14, 2023, is incorporated herein by reference in its entirety.

Various hydraulic pumps having fluid ends are commonly used in industrial applications to deliver high volumes of highly pressurized fluids during operations such as hydraulic fracturing (“fracking”). Some of these hydraulic pumps, as well as their benefits, are described in detail in the '710 patent.

This patent application describes an apparatus that improves prior high-pressure pumps in a variety of ways. The application describes various embodiments of a fluid end, as well as various methods of assembling, maintaining, operating, and repairing the fluid end.

Looking particularly to the pump described in the '710 patent, the “in-line” nature of the fluid end pump eliminates the need for intersecting bores, thus reducing the likelihood of stress and fatigue failures while increasing fluid end operational life. While this “in-line” pump technology is presented in the '710 patent, this patent application describes further innovative improvements in features and designs to the “in-line” pump. These features are described in detail herein.

One of these improvements is the introduction of a sleeve within the fluid end's plunger, which improves installation of a valve assembly. The sleeve is sized such that its orientation and geometry enable a user to at least partially compress the spring of the valve assembly while installing the valve assembly in the plunger. Further, instead of machining this profile into the inner diameter of the bore of the plunger, the sleeve provides a removable component that can be machined separate from the plunger and removed or replaced if needed. Thus, the sleeve, among other advantages, also provides an easier manufacturing process of the improved designs disclosed herein.

Another improvement within certain embodiments disclosed herein is a split “static” section of the fluid end. The split static section is divided into two pieces, which reduces the risk of cutting or harming dynamic seals during initial installation of “dynamic” sections into the static section. During construction of the fluid end, dynamic sections are threaded into a first piece of the static section, then essentially pushed straight into dynamic seals such that the dynamic seals surround at least a portion of the dynamic sections. The two static pieces are then combined, and the dynamic sections are further torqued into the combined static section as needed. By eliminating the step of rotating the dynamic sections directly into the dynamic seals, the risk of harming the dynamic seals is reduced. The installation and construction of the static and dynamic sections are described more herein.

Other improvements discussed herein include the addition of hardened inserts in areas subject to high erosion, such as surfaces that engage seals. The addition of hardened inserts reduces wear and erosion, which in turn increases the life of the parts in which such inserts are installed in.

Yet another improvement discussed herein is the introduction of a twist-on “locking” retainer. This retainer may be replaced with a bolt-on design, as desired. Both designs offer improved efficiencies in installing, replacing, and removing components of the fluid end.

In some embodiments, a packing sleeve may be inserted into a dynamic section or piece. Such packing sleeve may not have a hardened insert within; however, it should be noted that hardened inserts formed of carbide or other hard materials may be used in the sealing area between the packing sleeve and the dynamic section, and/or the sealing area between the packing sleeve and the packing.

In general, a fluid is routed through the fluid end by passing through a suction conduit, then into a plunger's internal bore. The fluid may then pass through a valve installed at one end of the plunger and into a cavity. The plunger may then extend into the cavity such that the fluid is pressurized. Once pressurized, the fluid may then pass through another valve, and out of a discharge port or conduit. The proceeding description should be understood to be a general example and overview of how the fluid end operates, and should not be misunderstood to be limiting in any way. There may be many ways to operate the fluid end described herein.

Referring now to the figures,show a fluid end. The fluid endcomprises a static section, a plurality of dynamic sections, a plurality of retainers, a plurality of retainer seals, a plurality of retainer locks, a plurality of packing stacks, a plurality of plunger assemblies, a plurality of packing nuts, a plurality of packing nut seals, a plurality of top plunger suction fittings, a plurality of bottom plunger suction fittings, and a plurality of suction fitting connectors.

Referring now to, the static sectioncomprises a front static section, a rear static section, a plurality of dynamic seals, a plurality of static section connectors, a plurality of discharge valve assemblies, a plurality of discharge plug seals, and a plurality of discharge plug retainers. In alternative embodiments, the static sectionmay comprise a single-piece body instead of sectionsand.

Referring now to, each discharge valve assemblycomprises a discharge valve, a spring, a discharge plug, and a dowel pin.

Referring now to, the front static sectionhas the general shape of a rectangular prism comprising a plurality of stay rod through holes, a plurality of flow bores, a plurality of rear static section mounting holes, and a discharge bore. The stay rod through holesare parallel to the flow boreswhich are formed perpendicular to the front surfaceof the front static sectionand parallel to the longitudinal axis of the fluid end. The stay rod through holesare spaced evenly about each flow bore.

Referring now to, each flow boreconnects the frontand rearsurfaces of the front static section. Beginning at the front surfaceand continuing along the bore axis to the rear surface, each flow borecomprises a threaded section, a discharge plug section, a chamber section, a dynamic section counterbore, and a dynamic seal counterbore. The discharge plug sectioncomprises a discharge plug seal groove.

Referring now to, the discharge boreconnects the leftand rightside surfaces of the front static section. The discharge borealso partially intersects each of the plurality of flow bores, specifically in the chamber sectionof each flow bore. The discharge borefurther comprises a counterboreand countersinkat the intersection of the discharge boreand each side surfaceandto facilitate the connection of discharge fittings (not shown).

Referring now to, the rear static sectionhas the general shape of a rectangular prism comprising a plurality of stay rod through holes, a plurality of dynamic section mounting bores, and a plurality of rear static section mounting holes. When the static sectionis assembled, the locations of the stay rod through holesalign with the stay rod through holesof the front static sectionon a one-to-one basis. The bore axes of the stay rod through holesare also collinear with the bore axes of each corresponding stay rod through holeon a one-to-one basis.

The dynamic section mounting boresare through bores connecting the frontand rearsurfaces of the rear static section. Each dynamic section mounting borehas an internal threadconfigured to receive a dynamic section. When the static sectionis assembled, the locations of the dynamic section mounting boresalign with the flow boresof the front static sectionon a one-to-one basis. The bore axes of the dynamic section mounting boresare also collinear with the bore axes of the flow boreson a one-to-one basis.

The rear static section mounting holesare through bores connecting the frontand rearsurfaces of the rear static section. Each rear static section mounting holehas a counterbore opening to the rear surfaceof the rear static section. When the static sectionis assembled, the locations of the rear static section mounting holesalign with the rear static section mounting holesof the front static sectionon a one-to-one basis. The bore axes of the rear static section mounting holesare also collinear with the bore axes of the rear static section mounting holesof the front static section.

Referring now to, the retainerhas a generally cylindrical shape comprising opposed frontand rearsurfaces connected by an intermediate outer surface. The retainerfurther comprises a through borethat also connects the frontand rearsurfaces. The bore axis of the through boreis collinear with the longitudinal axis of the retainer. Beginning at the front surfaceand continuing along the bore axis to the rear surface, each through borecomprises a retainer flange section, dynamic flange section, a packing section, and a packing nut section, as shown in.

The retainer flange sectioncomprises a plurality of cutouts. In this embodiment there are two cutouts, however there may be more if desired. Since the diameter of the retainer flange sectionof the through boreis smaller than that of the dynamic flange section, the cutoutsonly modify the retainer flange section. Radially, each cutoutremoves the entire portion of the retainerfrom the through boreradially outward to the intermediate outer surface, leaving a radial wallat the radial limits of each cutout, that is two for each cutout. Longitudinally, the cutoutbegins at the front surface, continues through the entire length of the retainer flange sectionand ends within the dynamic flange section, leaving a cutout surfaceat the longitudinal limit of each cutout.

The dynamic flange sectionof the through borehas a larger diameter than each adjacent section, thus creating a front shoulderand rear shoulder. The rear shoulderfurther comprises a seal groove.

The packing nut sectioncomprises an internal threadoriginating at the rear surfaceof the retainer. The packing nut sectionfurther comprises a thread reliefadjacent the packing sectionand the internal thread.

The retainerfurther comprises a lubrication portconnecting the intermediate outer surfaceto the packing sectionof the through bore. The lubrication portmay have internal threadsand/or a counterboreconfigured to accept a lubrication fitting (not shown) as needed.

Referring now to, each dynamic sectioncomprises a dynamic section body, a discharge valve seat, and a wear sleeve. Referring now tothe dynamic section bodyhas a generally cylindrical shape comprising opposed frontand rearsurfaces connected by an intermediate outer surface. The dynamic section bodyfurther comprises a through borethat also connects the frontand rearsurfaces. The bore axis of the through boreis collinear with the longitudinal axis of the dynamic section body. Beginning at the front surfaceand continuing along the bore axis to the rear surface, each through borecomprises a discharge valve seat section, a plunger section, a packing section, and a wear sleeve section, as shown in. The wear sleeve sectionmay not be present if no wear sleeveis used. If no wear sleeve sectionis present, the packing sectionwill extend to the rear surface.

The intermediate outer surfacealso has areas with different features. Beginning at the front surfaceand continuing to the rear surface, each intermediate outer surfacecomprises a dynamic seal section, an external thread, a retainer flange relief section, and a dynamic flange section. The retainer flange relief sectionhas a smaller diameter than dynamic flange section, thus forming a rear shoulderas part of the retainer flange relief section, as shown in.

The dynamic flange sectioncomprises a plurality of cutouts. In this embodiment, there are two cutoutsto match the number of cutoutsin the retainer. Since the diameter of the dynamic flange sectionis larger than that of the retainer flange relief section, the cutoutsonly modify the dynamic flange section. Radially, each cutoutremoves only a portion of the dynamic flange sectionfrom the intermediate outer surfacedown, that is radially, toward the longitudinal axis of the dynamic section body, but not all the way through to the through bore. The cutoutsthus form a radial wallat the radial limits of each cutout, that is two for each cutout. Longitudinally, the cutoutbegins at the rear surfaceand continues through the entire length of the dynamic flange section. The radial depth of the cutoutsis such that the rear shoulderheight is reduced, but the rear shoulderis not eliminated. The cutoutsalso form a cutout surfacethat is the radial base of the cutoutwith a diameter smaller than the diameter of the dynamic flange section.

Referring now to, the retainer lockhas the general shape of a quarter cylindrical section and comprises opposed frontand rear surfacesconnected by intermediate innerand outersurfaces. Beginning at the front surfaceand continuing along the longitudinal axis of the retainer lockto the rear surface, the intermediate outer surfacecomprises a front chamfer, a retainer section, a limit shoulder, a dynamic section, and a rear chamfer. The diameter of the retainer sectionis the same as the diameter of the intermediate outer surfaceof the retainer. The diameter of the dynamic sectionis the same as the diameter of the dynamic flange sectionof the intermediate outer surfaceof the dynamic section body. The diameter of the intermediate inner surfaceis the same, or nearly the same, as the cutout surfaceof the cutoutin the dynamic flange sectionof the intermediate outer surfaceof the dynamic section body. The retainer lockfurther comprises a plurality of radial walls. An alternative embodiment of the retainer lock may include a threaded hole and fastener, or other apparatus, to lock the retainer lock in position after assembly.

Referring now to, the discharge plughas a generally cylindrical shape comprising opposed frontand rearsurfaces connected by an intermediate outer surface. Beginning at the front surfaceand continuing along the longitudinal axis to the rear surface, the intermediate outer surfacecomprises outer limit section, a stop bevel, an assembly clearance section, a sealing section, a relief bore shoulder, a flow clearance section, a spring shoulderand a spring section.

The discharge plugfurther comprises a threaded tool borecentered on the front surface.

The discharge plugfurther comprises a blind valve stem borecentered on and originating from the rear surfaceand extending along the longitudinal axis to a depth coinciding with the approximate longitudinal position of the assembly clearance sectionon the intermediate outer surface. The valve stem boremay have a countersinkto facilitate assembly of the discharge valveif desired.

The discharge plugfurther comprises a plurality of relief boresconnecting the relief bore shoulderto the valve stem bore. The relief boreshelp alleviate accumulation and build-up of particulates and proppants within the valve stem bore. In this embodiment, there are six relief boresspaced evenly circumferentially, but there may be more or less spaced intermittently if desired. Each relief boreis angled from the longitudinal axis of the discharge plugsuch that the relief boreintersects the valve stem boreadjacent the baseof the valve stem bore. The angle of the relief boremay be adjusted as necessary depending on the spatial relationship between the relief bore shoulderand the baseof the valve stem bore.

The discharge plugfurther comprises a dowel pin bore. The dowel pin boreis perpendicular to and intersects the longitudinal axis of the discharge plug. The dowel pin boreis longitudinally positioned such that it intersects the intermediate outer surfacein the spring section. The dowel pin borealso intersects the valve stem bore. The dowel pin boremay have a countersinkto facilitate the insertion of the dowel pin.

Referring now to, the discharge valvecomprises a valve insertand opposed frontand rearsurfaces connected by an intermediate outer surface. Beginning at the front surfaceand continuing along the longitudinal axis of the discharge valveto the rear surface, the intermediate outer surfacecomprises an insert profile, a spring shoulder, and a stem section. The spring shouldercomprises a spring groove. The discharge valvefurther comprises a dowel slot. The dowel slotaids in installation and alignment, as discussed herein. The dowel slotis perpendicular to and intersects the longitudinal axis of the discharge valve. The dowel slotextends completely through the discharge valve. The dowel slotis located longitudinally on the stem section. In this embodiment, the longitudinal location of the dowel slotis proximate the spring shoulderbut may be located anywhere along the stem sectionas long as the entire dowel slotis contained within the stem section.

Referring now to, the top plunger suction fittingcomprises a riser sectionand a clamp section. The riser sectioncomprises an external threadand an insert section. The insert sectionhas a flow relief notch. The clamp sectioncomprises a plurality of attachment flangeswith a plurality of fastener through holesand in internal profilethat is complementary to the plunger assembly.

Referring now to, the bottom plunger suction fittingcomprises a plurality of attachment flangeswith a plurality of threaded fastener through holes. The bottom plunger suction fittingalso comprises an internal profilethat is identical to the internal profileof the top plunger suction fitting.

Turning now to, the plunger assemblyand its internal components are shown in greater detail. The plunger assemblycomprises a plunger body, or plunger, a suction valve seat, a sleeve, and a suction valve assembly.

The suction valve assemblycomprises a valve body, a valve retention system, and a valve return system. The suction valve seatmay be formed of a hardened material such as tungsten carbide. Such material resists wear and erosion, significantly extending the life of the suction valve seat.

Referring now tothe plungeris generally cylindrically shaped and comprises opposed frontand rearsurfaces connected by an intermediate outer surface. The plungerfurther comprises a suction bore. The suction boreis a blind bore that originates on the front surfaceand terminates proximate the rear surface. Beginning at the front surfaceand continuing along the bore axis to the rear surfaceof the plunger, the suction borecomprises a suction valve seat countersink, a suction valve seat counterbore, a sleeve counterbore, and a flow bore section. Beginning at the front surfaceand continuing along the longitudinal axis of the plungerto the rear surface, the intermediate outer surfacecomprises a packing section, a suction fitting section, and a pony rod clamp section. The plungerfurther comprises a suction fitting bore. The suction fitting boreis perpendicular to the longitudinal axis of the plunger. The suction fitting boreoriginates from the intermediate outer surfaceand terminates once it intersects the flow bore sectionof the suction bore.

The valve bodyhas opposed front and rear surfacesand. A sealing surfaceis formed at the rear surfaceof the valve bodythat corresponds with a tapered front surfaceof the suction valve seat. A socket connectionis formed on the front surfaceof the valve body.

The valve retention systemcomprises an elongate steminstalled within a retainer. The retainercomprises a central supportjoined to two tabs. The central supporthas a length that allows the central supportto engage the rear surfaceof the valve body. The stemhas a square cross-section that corresponds to a central passageformed in the central supportalso having a square cross-section. The stemis thus installed within the central passage. The square cross-sections prevent the stemfrom rotating when the valve assemblyis installed within the plunger. A first endof the stemis attached to the valve body, while an opposed second endof the stemis attached to a valve return system.

The valve return systemcomprises a spring stop, a spring, and a retainer pin. The springis disposed around the second endof the stemand the spring stopis attached to the second endof the stemvia the retainer pin. The springis thus situated on the stembetween the spring stopand the central supportof the retainer. When the suction valve assemblyis assembled, the retainerrotates with the stem, but is free to move longitudinally along the stem. The valve bodyand the stemmay be formed as a single, integrally formed piece, as shown in the Figures.

The valve retention systemis held within the plungerusing the sleeve. The sleeveis sized to fit within the plungerrearward of the suction valve seat, in the sleeve counterbore. The sleevemay be press-fit or interference fit within the plunger. Preferably, the sleeveis lightly press-fit into the plungerand is held in place by the tightly press-fitted suction valve seat. The sleeveis tubular with opposed end surfaces and comprises opposed openingsformed in the walls of the sleeve. Each openingincludes an installation slotand a relief notch, as shown in.

To install the valve retention systemwithin the plunger, the valve retention systemis inserted into the plungerand the sleevesuch that each tabpasses through a corresponding one of the installation slots. Once a tabis within the corresponding opening, the valve retention systemis rotated relative to the sleeveuntil each tabis forced into one of the corresponding one of the relief notches. The valve retention systemmay be turned or rotated using a tool (not shown) installed within the socket connectionformed in the valve body.

The valve retention systemis configured such that the springof the valve return systemis always at least partially compressed between the retainerand the spring stopof the valve return system. When the valve retention systemis installed within the sleeve, the springis further compressed as the tabsrotate within the corresponding openings. Once the tabsare forced into the corresponding relief notches, the springis still compressed and exerts a force against the bottom of the retainer, thereby holding the tabswithin the corresponding relief notchesand retaining the suction valve assemblywithin the sleeveand the plunger. During operation, the stemand valve bodymove relative to the retainer, the sleeve, and the plunger.

Referring now to, the assembly of the fluid endwill be discussed. First, the dynamic sealsare installed in the dynamic seal counterboresof the flow boresof the front static sectionof the static section, as shown in. Second, the dynamic sectionsare assembled by pressing the discharge valve seatsinto the discharge valve seat sectionsof the through boresof each dynamic section bodyand pressing the wear sleeveinto the wear sleeve sectionsof the through bores, as shown in. Third, each dynamic sectionis threaded into an internal threadof a dynamic section mounting boreof the rear static sectionuntil the dynamic seal sectionsprotrude from the front surfaceenough to fully engage the dynamic seals, as shown in.

Fourth, the protruding dynamic seal sectionsare aligned with the dynamic sealsalready installed in the front static section, and the front surfaceof the rear static sectionis abutted to the rear surfaceof the front static sectionwhile simultaneously inserting the dynamic seal sectionsinto the dynamic seals, as shown in. Fifth, the static section connectorsare inserted into the rear static section mounting holesof the rear static sectionand threaded into the rear static section mounting holesof the front static section, then torqued to specification, as shown in. Sixth, each dynamic sectionis threaded further into the internal threadof the dynamic section mounting boreit is already installed in until the front surfaceof the dynamic section bodyabuts the baseof the dynamic seal counterbore, as shown in. Seventh, the retainer sealsare inserted into the seal groovesin the rear shouldersof the dynamic flange sectionsof the through boresof each retainer, as shown in.

Eighth, the front surfaceof a retainerand the rear surfaceof a dynamic section bodyare oriented to face each other and the through boresandare aligned to be concentric, as shown in. Ninth, the retaineris oriented rotationally such that the cutoutsof the retaineralign with the non-cutout sections of the dynamic sectionand the cutoutsof the dynamic sectionalign with the non-cutout sections of the retainer, as shown in. Tenth, the retaineris advanced longitudinally over the dynamic sectionuntil the rear shoulderof the dynamic flange sectionabuts the rear surfaceof the dynamic section body, as shown in. Eleventh, the retaineris rotated about its longitudinal axis until the radial wallsof the retaineralign radially with the radial wallsof the dynamic section, as shown in.